Cupel muffle



Patented Aug. 21, 1945 PATENT OFFICE CUPEL MUFFLE Doty M. Steele, Los Angeles, Calif.

Application April 5,

1 Claim.

My invention relates to a cupel muflie and has for its principal object the provision of a relatively simple, practical, and inexpensive muflie which may be advantageously employed for the cupellation of ore buttons.

Further objects of my invention are to generally improve upon and simplify the construction of existing forms of cupel muflles and to provide asimple, compact muffle which may be conveniently utilized by assayers and likewise by prospectors or other persons who do not have ready access to furnaces or large mufflcs; and further, to provide a cupel muflie of the character referred to that may be readily heated by conventional means, for instance a blow torch.

A further object of my invention is to provide a mufile wherein the cupels occupy air chambers of air ample size and the tops of the cupels being opened to atmosphere thereby providing for free oxidization of the ore buttons placed in said cupels.

With the foregoing and other objects in view, my invention consists in certain novel features of construction and arrangement of parts which will be hereinafter more fully described and claimed and illustrated in the accompanying drawing.

Fig. 1 is a perspective view of a cupel mufile constructed in accordance with my invention.

Fig. 2 is a plan view of the base or main body of the mufile.

Fig. 3 is a cross section taken on the line 3-3 of Fig. 1. i

Fig. 4 is a cross section of a cupel and showing the pellet of previous metal recovered after the cupelling function.

Referring by numerals to the accompanying drawing which illustrates a preferred embodiment of my invention, It! designates the base or main body of the muflle which is substantially rectangular in form, composed of fire resistant material, for instance, fire clay or the like, and formed in the'upper portion of said body is a longitudinally disposed channel I I opened on the top of the body Ill and which channel is approximately rectangular in cross section.

At one or more points throughout the length of the body, channel II is increased in width so as to form cupel chambers I2 and which latter are preferably circular in shape. Formed in the lower portion of body II] just below the bottom surface of the channel I I are two or more longitudinally disposed parallel circulation ducts I3.

Removably positioned on the body I is a rectangular cover plate I4 composed of fire resist- 1943, Serial No. 481,875

ant material and formed in said cover plate are circular apertures I5 for the accommodation of the upper end portions of conventional cupels C which are positioned in the chambers I2 while undergoing the cupelling function. I

In the use of my improved mufiie, the cupels 0 containing the ore buttons B to be reduced, are placed centrally within the chambers I2, as illustrated in Fig. 2, after which coverplat I3 is positioned on top of the body ID with the upper portions of the cupels occupying the lower portions of the openings I5, and thus the pockets in the cupels are opened to the atmosphere and the chambers I2 and grooves I3 provide ample air and heat circulation space around and below the'cupels.

The mufile is now heated in any suitable manner, for instance, by means of a conventional blow torch held so that its flame is directed into 20 the end of the channel II, and thus, the ore button containing cupels are heated to such a degree as to oxidize the ore having a lower melting point than the precious metals, for instance, gold, silver and platinum, and a portion of the oxidized ore passes on into the atmosphere and other portions are absorbed by the porous bodies of the cupels, thus leaving the pellets P of precious metals in the cupels as illustrated in Fig. 4.

Among the particular advantages of my improved cupel muffle is the compact structure which enables it to be conveniently packed, transported and handled, further, the provision of ample air and heat circulation chambers around the cupels, and further, the arrangement whereby the metal buttons containing pockets in the cupels are open to atmosphere, thus enabling cupelation of the fumes of oxidation from the ore button within the cupel directly into the atmosphere and eliminating the necessity for a large and cumbersom closed muflle, all of which provisions render the muffle highly effective in performing its intended functions.

It will be understood that minor changes in the size, form and construction of the various parts of my improved cupel mufile may be made and substituted for those herein shown and described without departing from the spirit of the invention, the scope of which is set forth in the which is substantially greater than the cupel positioned in said chamber, so that the entire outer face of the cupel within said chamber is exposed to atmosphere, there being a pair of longitudinally disposed parallel grooves formed in the bottom of said channel, the ends of which grooves are open, the intermediate portions of which grooves communicate with said cupel chamber and a one piece cover plate removably positioned on said base for wholly covering said channel, which cover plate is provided with an aperture, the size of which is such as to snugly receive the upper edge of the cupel positioned in the cupel chamber, so that the pocket in said cupel is open to atmosphere.

DOI'Y M. STEELE. 

